Well, there's an answer that briefly covers the politics of it here in a past post, but it doesn't really address if anyone truly cared. However I can say that ethnic Germans and supporters of the Habsburg monarchy truly did care. The Archduke was the determined successor to the Austrian-Hungarian throne, the man who was trained to take up the throne after the death of the elderly Franz Josef I, who at the time was 84. Blaming it on the Austrains is a mix of post-war Entente history and accurate. The Austrians delivered an extremely harsh ultimatum to Serbia, which Serbia filled almost completely, but falling short of the Austrian's intentionally unreasonable ultimatum. While the Prime Minister of Hungary Count Istvan Tisza cited that starting a war with Serbia would draw Russia and possibly France into the war, the Chief of Staff for the Army of Austria-Hungary as well as the Germans believed that war was the best answer, with Franz Josef agreeing that war would be a preferable choice if the Germans were to support them. Anyhow, this event shocked the monarchy and they were in support of the war, with the exception of the Hungarians who displayed a certain clairvoyance as to what would happen. As for the people of the empire, they were too in favor of the war. Massive anti-Serb demonstrations wracked the country as the people (German people at least) we outraged at what appeared to be a nationally sanctioned Serbian plot against the Habsburg monarchy. While it cannot be said what the feelings were concerning other ethnicities as to what their feelings were towards the matter, it can be said that they answered the call to arms, less reluctantly than they might have otherwise. While this is a brief explanation, I can recommend a book that has helped me glean more knowledge on the subject. If there's anything I need to clean up for further explain, don't be afraid to tell me as I'm rather tired at the moment.